• The Journal of Korean Academy of Prosthodontics
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• v.57 no.3
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• pp.211-218
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• 2019

Purpose: The purpose of the present study was to compare the accuracy of four different metal copings fabricated by CAD/CAM technology and to evaluate clinical effectiveness. Materials and methods: Composite resin tooth of the maxillary central incisor was prepared for a metal ceramic crown and duplicated metal die was fabricated. Then scan the metal die for 12 times to obtain STL files using a confocal microscopy type oral scanner. Metal copings with a thickness of 0.5 mm and a cement space of $50{\mu}m$ were designed on a CAD program. The Co-Cr metal copings were fabricated by the following four methods: Wax pattern milling & Casting (WM), Resin pattern 3D Printing & casting (RP), Milling & Sintering (MS), Selective laser melting (SLM). Silicone replica technique was used to measure marginal and internal discrepancies. The data was statistically analyzed with One-way analysis of variance and appropriate post hoc test (Scheffe test) (${\alpha}=.05$). Results: Mean marginal discrepancy was significantly smaller in the Group WM ($27.66{\pm}9.85{\mu}m$) and Group MS ($28.88{\pm}10.13{\mu}m$) than in the Group RP ($38.09{\pm}11.14{\mu}m$). Mean cervical discrepancy was significantly smaller in the Group MS than in the Group RP. Mean axial discrepancy was significantly smaller in the Group WM and Group MS then in the Group RP and Group SLM. Mean incisal discrepancies was significantly smaller in the Group RP than in all other groups. Conclusion: The marginal and axial discrepancies of the Co-Cr coping fabricated by the Wax pattern milling and Milling/Sintering method were better than those of the other groups. The marginal, cervical and axial fit of Co-Cr copings in all groups are within a clinically acceptable range.

• Korean Journal of Heritage: History & Science
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• v.49 no.2
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• pp.56-69
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• 2016

Flame resistant treatment has been applied since 1973 for fire prevention in historical wooden buildings, but several problems, such as whitening and discoloration are constantly occurring in some Dancheong, in spite of evaluation criteria. It is supposed that these phenomena are caused by the stability issue of flame retardant, Dancheong production methods, the residue of chemicals, which were applied in the past, building location environments, etc., but no evaluation and cause inspection has been performed. Therefore, this study aims to verify the effect of flame retardant on Dancheong by producing Pseudo-samples and setting spatial and temporal environment conditions. Pseudo-samples of Dancheong were produced using three methods; the method specified in the Standard Specification of Properties; the method, which is generally used in the site and the traditional method. For different environment conditions of pseudo-samples, the areas were classified into a coastal area and an inland area and the places were classified into a sunny place and a wetland. After applying a flame retardant, annual variations were inspected for 12 months and change aspects were observed through scan and regular observation. In annual variation inspection, various variations like whitening, decolorization, dissolution and exfoliation were found and especially, whitening was most dominant. When the effect of flame retardant depending on the production methods was analyzed, whitening occurred in all the three production methods. It is supposed that this is because calcium(Ca) was contained in the coloring material of each production method and it reacted with phosphorous(P) of flame retardant. When the effect of flame retardant depending on the environment conditions was analyzed, whitening occurred more in the coastal area than in the inland area and it reduced in the building in a sunny place, which was constructed using the traditional method. It is supposed that this results from the humidity change and the difference of glue used in each production method. In conclusion, for using a flame retardant containing phosphorous(P), there is a need to check if calcium components including Oyster Shell White were used in Dancheong in advance and to conduct various preliminary studies on place conditions and Dancheong construction conditions.

• Journal of Korea Water Resources Association
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• v.54 no.6
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• pp.419-431
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• 2021

In Seoul, it has been confirmed that the duration of rainfall is shortened and the frequency and intensity of heavy rains are increasing with a changing climate. In addition, due to high population density and urbanization in most areas, floods frequently occur in flood-prone areas for the increase in impermeable areas. Furthermore, the Seoul City is pursuing various projects such as structural and non-structural measures to resolve flood-prone areas. A disaster prevention performance target was set in consideration of the climate change impact of future precipitation, and this study conducted to reduce the overall flood damage in Seoul for the long-term. In this study, 29 GCMs with RCP4.5 and RCP8.5 scenarios were used for spatial and temporal disaggregation, and we also considered for 3 research periods, which is short-term (2006-2040, P1), mid-term (2041-2070, P2), and long-term (2071-2100, P3), respectively. For spatial downscaling, daily data of GCM was processed through Quantile Mapping based on the rainfall of the Seoul station managed by the Korea Meteorological Administration and for temporal downscaling, daily data were downscaled to hourly data through k-nearest neighbor resampling and nonparametric temporal detailing techniques using genetic algorithms. Through temporal downscaling, 100 detailed scenarios were calculated for each GCM scenario, and the IDF curve was calculated based on a total of 2,900 detailed scenarios, and by averaging this, the change in the future extreme rainfall was calculated. As a result, it was confirmed that the probability of rainfall for a duration of 100 years and a duration of 1 hour increased by 8 to 16% in the RCP4.5 scenario, and increased by 7 to 26% in the RCP8.5 scenario. Based on the results of this study, the amount of rainfall designed to prepare for future climate change in Seoul was estimated and if can be used to establish purpose-wise water related disaster prevention policies.

• Korean Journal of Remote Sensing
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• v.37 no.3
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• pp.419-430
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• 2021

Remote sensing techniques using drone-based multispectral image were studied for fast and two-dimensional monitoring of algal blooms in the river. Drone is anticipated to be useful for algal bloom monitoring because of easy access to the field, high spatial resolution, and lowering atmospheric light scattering. In addition, application of multispectral sensors could make image processing and analysis procedures simple, fast, and standardized. Spectral indices derived from the active spectrum of photosynthetic pigments in terrestrial plants and phytoplankton were tested for estimating chlorophyll-a concentrations (Chl-a conc.) from drone-based multispectral image. Spectral indices containing the red-edge band showed high relationships with Chl-a conc. and especially, 3-band model (3BM) and normalized difference chlorophyll index (NDCI) were performed well (R²=0.86, RMSE=7.5). NDCI uses just two spectral bands, red and red-edge, and provides normalized values, so that data processing becomes simple and rapid. The 3BM which was tuned for accurate prediction of Chl-a conc. in productive water bodies adopts originally two spectral bands in the red-edge range, 720 and 760 nm, but here, the near-infrared band replaced the longer red-edge band because the multispectral sensor in this study had only one shorter red-edge band. This index is expected to predict more accurately Chl-a conc. using the sensor specialized with the red-edge range.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.29 no.2
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• pp.139-148
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• 2011

This study has a purpose of base study for ascertaining landscape architect's role of Reung Chambong through analyzing old literature include Kyungkukdae-Jeon, Sokdae-Jeon, Daejeonhoitong, Joseonwangjo-Sillok, Eugye, Reung-Ji, Ilsung-Rok, Reung Chambong's diary. Reung Chambong was a government post in the Joseon dynasty, who managed Royal Tombs of Joseon Dynasty that has promoted as a World Heritage of UNESCO. the conclusions drawn from this study are as follows. First, Reung Chambong was comprised of two Jong 9 pum Chanmbong members. a position of Reung Chambong was a Eumjik appointed Saengwon, Jinsa, Yuhak completed Sammang. the standards of appointment is a experienced person and too young. it became means for accessing a government post because it had a symbolic representation of Royal Tombs guardian. Second, The management system of Reung Chambong was approved on the basis of ranking. however, due to geographical reasons, they had much authority and various mission than is possible. for example, construction supervisor of the Reung and Bongsim, manager of the Reungsuhogun and filling out Reungji. they performed an important role in management of Royal Tombs in the Joseon dynasty. Third, One of tasks related in landscape architecture, a Bongshim reported Sukmul(stonework), Sacho, Jungja-Gak of Reungsang to Yejo periodically. formational system and method of Bongshim are provided in the Kyungkukdae-Jeon and Sokdae-Jeon detailedly. Fourth, Tree management and construction supervisor of Reungsang, positions among tasks related in landscape architecture, required basic understanding and management ability of botany, various eye for spatial perception includes civil and architectural projects. also, as a site management of Royal Tombs in the Joseon dynasty, Reung Chambong was empowered tacit authorization and responsibility in mobility preoccupancy of vertical relationship with local officials and handling by-product of site. there is a close correspondence with landscape architect of today. A follow-up research is required to ascertain landscape architect historical values of Royal Tombs in the Joseon dynasty and Reung Chambong's role as a site management of Royal Tombs in the Joseon dynasty through historical seeking and research old literature on Reung Chambong's role related in landscape architect.

• The Korean Journal of Nuclear Medicine Technology
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• v.25 no.2
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• pp.29-34
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• 2021

Purpose Sample reception environment system in nuclear medicine has not changed much compared to 20 years ago. When preparing sample for in vitro test, there was no significant change because the test was carried out by generating an own specimen from the parent specimen. In this study, We would like to introduce a method that automatically removes the sample cap using the automated decapper equipment and enables automatic reception at the same time. In addition, including a provisional reception system. Materials and Methods In 2019, it was intended to get a device that automatically removes the cap of a patient's blood sample. This equipment is the same as the equipment used in the Department of Laboratory Medicine (Vacuette Ⓡ Unicap Belt Decapper, Greiner bio-one, Austria). However, the purchase was delayed due to differences in tube size, budget, and space. In January 2020, we borrowed domestic automatic decapper equipment and modified it to suit our laboratory environment. After 9 months, we were able to introduce a system that automatically removes the lid of a patient's blood sample and at the same time automatically accepts the test. And, through the provisional reception system, it was possible to know the arrival of the specimen in a short time. Results With the use of an automatic decapper device, the sample cap was automatically removed, and the reception proceeded at the same time. So, it was very efficient at work because it shortened the sample preparation time by about 20 minutes. In addition, it was possible to prevent the examiner's musculoskeletal disorders caused by repeated wrist use. After using the provisional reception system, patients were able to be discharged quickly, and the number of phone calls to confirm the arrival of samples was reduced. Conclusion Most hospitals have about four employees in the nuclear medicine in vitro laboratory. It is effective to use automatic decapper equipment and a provisional reception system for organizations that perform work with the minimum number of personnel.

• Korean Journal of Heritage: History & Science
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• v.55 no.1
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• pp.243-263
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• 2022

The royal court of Joseon had a tradition of mounting the Irworobongdo, a painting of the sun, the moon and the five sacred peaks, symbols of the king's immortal presence and authority, on a folding screen and placing it in special spaces within the palace that were reserved for the king. While the Irworobongdo is generally accepted as the important ceremonial object of the royal palaces of Joseon, there have been few studies on the various folding screens used in the royal palaces, largely because the official records about such screens do not match the remaining original relics. In this study, the main discussion is focused on the diversity of the shapes and mounting materials of the Irworobongdoused for various ceremonies held in the royal palaces of Joseon based on the Uigwe, the official records of the royal protocols of the Joseon dynasty. The discussion also extends to the theme rarely studied so far, namely the original form of the Irworobongdo and its evolution in the following period. The ceremonial "five peak" folding screens (Obongbyeong) used at a number of important palace buildings, including the crown hall (Jeongjeon), royal funerary hall (Binjeon), spirit hall (Honjeon) and portrait shrine (Jinjeon), differed in shape and size from the folding screens used in royal celebratory events such as banquets, although the paintings themselves and the style of mounting them were essentially the same. The paintings were mounted on screens bordered with green silk and ornamented with floral gilt designs. The folding screens used in royal ceremonies were produced according to strict guidelines that required the ceremonies and mounting materials to be graded on the basis of the status of each screen. It was not until the 1960s that these ceremonial folding screens of the Joseon dynasty, which had been neglected during the period of Japanese colonial rule of Korea, began to undergo conservation treatment provided as part of a heritage preservation program. Unfortunately, many of the screens repaired in this period lost some of their original features - largely due to the use of non-traditional mounting techniques. Considering, however, that significant achievements have since been made in the heritage preservation field based on the use of historical evidence, it is now necessary to systematically use the repair history of the information about the remaining royal ceremonial folding screens to ensure that they are preserved and managed more effectively in the future.

• Economic and Environmental Geology
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• v.55 no.5
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• pp.551-561
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• 2022

Geophysical exploration methods are very useful for generating high-resolution images of underground structures, and such methods can be applied to investigation of buried cultural properties and for determining their exact locations. In this study, image feature extraction and image segmentation methods were applied to automatically distinguish the structures of buried relics from the high-resolution ground-penetrating radar (GPR) images obtained at the center of Silla Kingdom, Gyeongju, South Korea. The major purpose for image feature extraction analyses is identifying the circular features from building remains and the linear features from ancient roads and fences. Feature extraction is implemented by applying the Canny edge detection and Hough transform algorithms. We applied the Hough transforms to the edge image resulted from the Canny algorithm in order to determine the locations the target features. However, the Hough transform requires different parameter settings for each survey sector. As for image segmentation, we applied the connected element labeling algorithm and object-based image analysis using Orfeo Toolbox (OTB) in QGIS. The connected components labeled image shows the signals associated with the target buried relics are effectively connected and labeled. However, we often find multiple labels are assigned to a single structure on the given GPR data. Object-based image analysis was conducted by using a Large-Scale Mean-Shift (LSMS) image segmentation. In this analysis, a vector layer containing pixel values for each segmented polygon was estimated first and then used to build a train-validation dataset by assigning the polygons to one class associated with the buried relics and another class for the background field. With the Random Forest Classifier, we find that the polygons on the LSMS image segmentation layer can be successfully classified into the polygons of the buried relics and those of the background. Thus, we propose that these automatic classification methods applied to the GPR images of buried cultural heritage in this study can be useful to obtain consistent analyses results for planning excavation processes.

• Korean Journal of Agricultural and Forest Meteorology
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• v.25 no.2
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• pp.80-98
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• 2023

This study explores the effectiveness of various data preprocessing algorithms for improving subseasonal to seasonal (S2S) climate predictions from six climate forecast models and their Multi-Model Ensemble (MME) using a deep learning-based postprocessing model. A pipeline of data transformation algorithms was constructed to convert raw S2S prediction data into the training data processed with several statistical distribution. A dimensionality reduction algorithm for selecting features through rankings of correlation coefficients between the observed and the input data. The training model in the study was designed with TimeDistributed wrapper applied to all convolutional layers of U-Net: The TimeDistributed wrapper allows a U-Net convolutional layer to be directly applied to 5-dimensional time series data while maintaining the time axis of data, but every input should be at least 3D in U-Net. We found that Robust and Standard transformation algorithms are most suitable for improving S2S predictions. The dimensionality reduction based on feature selections did not significantly improve predictions of daily precipitation for six climate models and even worsened predictions of daily maximum and minimum temperatures. While deep learning-based postprocessing was also improved MME S2S precipitation predictions, it did not have a significant effect on temperature predictions, particularly for the lead time of weeks 1 and 2. Further research is needed to develop an optimal deep learning model for improving S2S temperature predictions by testing various models and parameters.

• Journal of the Daesoon Academy of Sciences
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• v.21
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• pp.199-254
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• 2013

대순사상은 인간의 행위와 정신적 틀, 즉 몸과 마음을 닦고 세상을 다스리며 백성을 평안하게 하는 도리를 설파하고 있다. 우주 공간의 질서와 깊은 연관을 맺는 이러한 도리는 인간 자신의 인지(認知)와 심신 수양의 내용을 포함하며, 사람이 사회와 우주자연과의 관계를 어떻게 처리해 나갈 것인지에 관한 문제도 다루고 있다. 따라서 대순사상을 인문이라는 관점에 입각하여 분석해 볼 필요가 있다. 이탈리아에서 시작된 서양의 인문주의와 비교해 볼 때, 중국 전통의 인문정신은 인류 개체의 창조력과 그 성과를 인정하고, 인격적 수양과 개선을 주장하며, 사회의 조화를 강조하는 한편, 인류가 반드시 천지인의 조화로운 관계 속에서 개체와 전체의 생존을 파악해야 함을 강조한다. 이러한 인문정신은 『전경』에서도 찾아볼 수 있다. 그 하나가 모악산과 단주(丹朱)에 대한 서술인데, 모악산은 산 즉 '간'(艮)괘이며 단주는 적색에 상응하니 곧 '리'(離)괘가 된다. 이 두 괘가 서로 조합하면 '비(比)'괘가 되며, 『주역』의 비괘와 연관하여 서로 간의 모순을 없애고, '바둑'을 두는 기법을 거울삼아 심성을 다스리며, 인격을 완성하고, 인신이 조화를 이루도록 하며, 사회를 안정시킬 것을 말한다. 대순 신앙의 최종 목표는 지상천국을 건설하는 것인데, 이런 목표를 실현하기 위해서는 인격수양을 그 출발점으로 삼아야 한다. 인격수양의 목표는 바른 도인이 되기 위한 것이며, 이를 위해서는 수도 공부를 해야만 한다. 수도는 춘추시기 노자 이래로 유구한 문화적 전통을 지닌 것이지만, 대순진리회는 한국사회 역사의 경향과 현실의 필요에 부응하여 수도 이론을 새롭게 수립하였다. 이를 살펴보면, 대순진리회는 수도자가 '성(誠), 경(敬), 신(信)'에 힘쓰는 품격 함양을 매우 중시한다. 또 도인들이 가정의 화목에 힘써야 하며, 솔선수범하는 도인으로서 사회의 모범이 되어야 한다고 말한다. 이렇게 볼 때, 대순진리회는 '인도'(人道)를 함양함을 강조하고 있으며, 이것은 전통적인 유가에서 말하는 '수신, 제가' (修身, 齊家)의 정신과 그 의미가 맞닿아 있다. 또한 중국 도교의 '선도(仙道)를 이루고자 하면 먼저 인도(人道)를 행하라'는 사상적 취지와도 일치한다. 대순진리회에서 수도의 최종 목표는 도통이다. 도통은 수도자가 매우 높은 경지에 이르게 되었을 때 가지는 특수한 능력과 정신의 경지이다. '도통'에 대한 기록은 『장자·제물론』, 『문자』의 「부언편>(符言篇) 등에서 찾아볼 수 있는데, 대순진리회가 말하는 도통은 중국의 도가 전통에 보이는 도통과도 연관되지만 강한 인륜수양(人倫修養)적 특색을 지니고 있다는 점에서 차이가 있다. 이것은 대순진리회가 가지는 중요한 인문적 함의라 하겠다. 대순진리회는 수도 공부로써 광제창생·보국안민·지상천국건설의 사회적 이상을 실현하고자 한다. 조화로운 사회적 관계를 수립하기 위한 토대는 대순진리회의 종지 첫 번째인 음양합덕이다. 음양합덕은 대순진리의 인문 취지의 이론적 기초를 형성하는 사상이다. 음양합덕의 철학적 사고는 종지 두 번째인 신인조화(神人調化)의 이상으로 이어진다. 신인조화는 『상서·순전』(尙書·舜典)의 신인이화(神人以和)에서 그 사상적 연원을 찾아 볼 수 있다. 다만 신인이화가 율려 조화의 '결과'를 표현한 것이라면, 신인조화에서 중시하는 것은 '과정'이며 인간과 신의 상호작용이라는 점에 그 특징이 있다. 신인조화를 이루기 위해서는 공부를 해야 하며, 그 배후에는 인본(人本)의 사상이 깃들어 있다. 그것은 종지 세 번째인 '해원상생'의 내용에서 더욱 명확하게 드러난다. 신인조화가 인간과 신의 관계를 조화롭게 하는 것을 말한다면, 해원상생은 인간과 인간의 관계를 조화롭게 하는 것을 말한다. 또 다른 한편으로는 긴 역사의 과정 속에서 맺힌 원을 풀어 우주의 기운을 잘 통할 수 있게 하고 인간 사회의 정상적인 교류를 이루도록 한다. 이러한 내용은 사회적인 인문적 관심과 배려를 다분히 포함하고 있는 것이다. 대순진리회의 종지 네 번째인 도통진경은 수도의 가장 높은 경지를 말하는데, 이러한 이념은 노장 일파의 도가 학자들이 말한 순박한 본성으로 회귀하자는 정신에서 그 원류를 찾을 수 있을 것이다. 또한 이는 한진(漢晉)시대 이래 중국 도교가 추구했던 '진경' 의 의미와도 합치된다. 그러나 시대와 환경이 다름으로 인해, 대순진리회의 '진경'은 사회생활의 의미까지 내포한다. 비록 대순진리회의 경전이 인본(人本)을 명확히 밝히고 있지는 않으나, 대순진리회의 요의(要義) 중 하나인 인존사상은 대순진리회의 인문정신을 말해주는 것이다. 인존사상의 직접적인 기능은 평안(平安)으로서 삶을 이롭게 하는 것이다. 대순진리회는 우주대원의 진리를 '도'라 하였는데 이러한 '도'는 중국의 도가에서 말하는 '도'와 동일하며, 여기에는 '안(安)'의 의미가 포함되어 있다. 대순진리회의 신조 중 '안심', '안신'은 마음을 정(靜)하게 하고, 몸을 편하게 하는 것으로 볼 수 있지만, 심신의 공포와 두려움을 떨쳐내어 안전과 보호를 얻는다는 의미도 있으므로 결국 평안이 전제가 된다. 이렇듯 대순진리회에서는 '평안에 대한 희구'를 근본으로 하여 신앙인들이 열심히 수도에 정진하고 있다. 대순진리회가 인류 평안을 기본으로 하는 종교라는 점에서, 반드시 세인들의 환영을 받을 것임을 믿어 의심치 않는다.